package com.springboot2.security.base.security.filter;

import com.springboot2.security.base.security.service.MyAccessDecisionManager;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.access.SecurityMetadataSource;
import org.springframework.security.access.intercept.InterceptorStatusToken;
import org.springframework.security.web.FilterInvocation;
import org.springframework.security.web.access.intercept.FilterInvocationSecurityMetadataSource;
import org.springframework.security.web.access.intercept.FilterSecurityInterceptor;
import org.springframework.stereotype.Service;

import javax.servlet.*;
import java.io.IOException;

/**
 * 过滤请求资源实现类
 *
 * @param
 * @author liucancan
 * @date 14:03 2018/12/12
 * @return
 */
@Service
public class MyFilterSecurityInterceptor extends FilterSecurityInterceptor implements Filter {

    @Autowired
    private FilterInvocationSecurityMetadataSource securityMetadataSource;

    @Autowired
    public void setMyAccessDecisionManager(MyAccessDecisionManager myAccessDecisionManager) {
        super.setAccessDecisionManager(myAccessDecisionManager);
    }

    @Override
    public void init(FilterConfig filterConfig) {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        FilterInvocation fi = new FilterInvocation(servletRequest, servletResponse, filterChain);
        invoke(fi);
    }

    /**
     * 每一个请求都会拦截
     * fi里面有一个被拦截的url
     * 里面调用MyInvocationSecurityMetadataSource的getAttributes(Object object)这个方法获取fi对应的所有权限
     * 再调用MyAccessDecisionManager的decide方法来校验用户的权限是否足够
     *
     * @param fi
     * @return void
     * @date 14:30 2018/12/13
     */
    @Override
    public void invoke(FilterInvocation fi) throws IOException, ServletException {
        InterceptorStatusToken token = super.beforeInvocation(fi);
        try {
            //执行下一个过滤器
            fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
        } finally {
            super.afterInvocation(token, null);
        }
    }

    @Override
    public void destroy() {

    }

    @Override
    public Class<?> getSecureObjectClass() {
        return FilterInvocation.class;
    }

    @Override
    public SecurityMetadataSource obtainSecurityMetadataSource() {
        return this.securityMetadataSource;
    }
}
